Monad Exercises

Monad1Exercise.scala

import language.higherKinds
trait Monad1[M[_]] {

  def id[A](a: A): M[A]

  def compose[A,B,C](f: A => M[B], g: B => M[C]): A => M[C]

  def flatMap[A,B](ma: M[A], f: A => M[B]): M[B] = ???

  def join[A](mma: M[M[A]]): M[A] = ???

  def ap[A,B](ma: M[A], mab: M[A => B]): M[B] = ???

  def map[A,B](ma: M[A], f: A => B): M[B] = ???

}

Monad2Exercise.scala

import language.higherKinds
trait Monad2[M[_]] {

  def id[A](a: A): M[A]

  def flatMap[A,B](ma: M[A], f: A => M[B]): M[B]

  def compose[A,B,C](f: A => M[B], g: B => M[C]): A => M[C] = ???

  def join[A](mma: M[M[A]]): M[A] = ???

  def ap[A,B](ma: M[A], mab: M[A => B]): M[B] = ???

  def map[A,B](ma: M[A], f: A => B): M[B] = ???

}

Monad3Exercise.scala

import language.higherKinds
trait Monad3[M[_]] {

  def id[A](a: A): M[A]

  def map[A,B](ma: M[A], f: A => B): M[B]

  def join[A](mma: M[M[A]]): M[A]

  def flatMap[A,B](ma: M[A], f: A => M[B]): M[B] = ???

  def compose[A,B,C](f: A => M[B], g: B => M[C]): A => M[C] = ???

  def ap[A,B](ma: M[A], mab: M[A => B]): M[B] = ???

}